Automatic cut-off for electrically-heated devices.



H. W. DENHARD. AUTOMATIC CUT-OFF FOR ELECTRICALLY HEATED DEVICES.

APPLICATION FILED JAN-30.19II. RENEWED DEC. 4.1912.

1,143,573. Patented June 15, 191.5.

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digaam a UNITED STATES PATENT OFFICE.

HARRY W. DENHARD, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO THE CUTLER HAMMER MFG. (10., OF MILWAUKEE, WISCONSIN, A CORPQRATION OF WIS' GONSIN.

AUTOMATIC CUT-OFF FOR ELECTRICALLY-HEATED DEVICES.

Specification of Letters Patent.

Application filed January 30, 1911, Serial No. 605,343. Renewed December 4, 1912. Serial No. 734,984.

To all whom it may concern:

Be it known that I, HARRY.W. DENHABD, a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of Wisconsirnhave invented new andthis specification.

My invention relates to improvements in automatic cutoffs for electrically heated devices.

The invention herein disclosed is another species of the generic invention set forth and claimed in my 00- ending application,

' Serial No. 57 9,845, file August 3, 1910.

"In order that my present invention may be fully and clearly understood, I shall describe the embodiment thereof illustrated in the accompanying drawing. It should be understood, however, that the present invention is not limited to the specific device illustrated.

In the accompanying drawing, Figure 1 is a longitudinal sectional view through the body of the iron with parts of the handle shown in section-and the remainder in elevation. Fig. 2 is a perspective view of the switch releasing device.

The iron illustrated is of the same general construction as that shown in my co-pending application aforesaid, and I shall therefore only briefly describe like parts herein. The body portion of the iron is formed in two sections '1 and 2. The lower section 1 is formed hollow to receive the heating unit 3 which is interposed between layers 4 of suitable insulating material. The unit is held in place against the bottom of the ,section 1 of the iron by aiplate 5 having lugs 6 hear ing against an insulating mat 7 interposed between the sections 1- and 2. The section 2' is secured to. the section 1 by suitable means, such as screws 8 only one of which is apparent;

Secured to the top of ortion 2 as by means of screws 9 is a hen le frame carrying a handle 11 within which is arranged a switch through whic pending application aforesaid whereby the switch 12 controls the connections between the terminal members and element 3. The switch mechanism is provided with an operating member 15 having on its under side a notched portion 16 adapted to be engaged by a vertically movable member 17 slidably mounted on the forward end of the handle frame. The switch 12 isbiased to open position and is held in closed position by engagement of the member 17 with the operating member 15 in the manner aforesaid. The member 17 is biased to holding position by a spring 17*.

I shall now describe in detail the characteristic parts of the iron herein illustrated.

WVithin a recess arranged in the bottom face of the interior of the portion 1, which recess preferably extends longitudinally of the iron, is a controlling device for the switch mechanism 12. This controlling device preferably comprises a brass bar 20 and an iron strip, or plate 21, secured to the under side'thereof by any suitable means such as screws 22. It is not essential that the iron plate be secured to the under side of the brass bar 20, or. that these particular metals be employed, but this is the preferred construction. The brass bar is in turn provided with an upwardly extending lug 23, which is secured by any suitable means such as screws 24, to the rear wall of portion 1 of the iron. It is'preferred that the bar 20 be rigidly secured to the iron. The iron plate or strip 21 is preferably extended slightly beyond the forward end of the bar 20 and provided with a recess 25 Patented June 15, 1915. I

preferably rectangular and partially covered by the end of the bar 20. The control.-

ling device is provided with a third member 4 tion of the member 26 to the device is such as to provide a fulcrum for the former. To the forward end of the member 26 is attached a substantially vertically disposed member 29 which for a purpose hereinafter set forth is preferably connected to the member 26 in themanner illustrated. This connection is formed by notching the lower extremity of the member 29 on opposite sides and blfurcating and recessing?the forward extremity of the member 26 so that when the extremities of the members 29 and 26 are interfitted' they will be firmly secured together, ,but will be permitted a slight relative play. Riveted, or otherwise rigidly secured to the member 29 is a' pin 30 projecting through the section 2 of the iron. The

upper extremity of the pin 30 is screwthreaded. An internally screw-threaded cap 31 having a head 32 is screwed onto the threaded portion of the pin 30. The mem- --ber .17 is provided with a forwardly extending lug 33 through which the'pin 30 projects. Thus when the cap 31 is secured onto the pin 30 the head thereof will bear against the upper face of the lug 33.

. Tightly clamped to the cap 31 below the lug I 33 is a pointer 34:. With this arran ement the member 17 and pin 30 are secure y fastened together to move in unison in both directions, while the cap 31 is free to be rotated in either direction relatively to the pin 30 by-means of the pointer34: which, as

above set forth, is tightly clamped thereto.

Such rotation ,of the cap 31'will through its screw-threaded connection with the 'pin-30 cause a relative adjustment between the member "17 and hemember 26 of the switch controlling device. The purpose of this adjustment will be hereinafter explained.

-' I shall now describe the purpose andfunctions of the various parts described.

Let it be assumed that the switch is in the position illustrated with the member 17 in engagement with the notched portion of the operating member 15 of the switch. The

' switc'hin thisfposition completes the circuit .of the heating unit of the iron and is retained in this position so long as the member 17 remains .in engagement with the notched portion. of the operating member 15. When these parts aredisengaged. the switch being biased to open positioniautomatically breaks the circuit of the heating unit. 3. I With proper adjustment between-the member l7 and the member 26 of the switch controlling device the member 17 will be held in engagement with the notched portion of the member 15 so long as the member 26 remains in normal position, as illustrated, and until said member is. moved to a predetermined degree. Here it should be noted that the member 26 due to its inherent tendency to remain in the position illustrated cooperates with the spring 17 of the retaining -difi:'erent coefiicients of expansion, the expansion. of brass being greater than that of iron. Bearing this in mind it will be seen that upon an increase in the temperature of the electrically heated device the brass bar 20 willexpand longitudinally to a greater degree than the iron strip 21, thereby pressing forwardly against the member 26. Pressure thus exerted against the member 26 will cause the'same to be tilted downwardly thereby exerting a pull upon the pin 30, which in turn tends to withdraw the member 17 from engagement with the operating member of the switch.' When the member 2.6 has been tilted to a predetermined degree disengagement of the members-15 and 17 isaccomplished whereupon the switch opens and disconnects the heating unit 3 from circuit. It will thus be seen that by proper design and adjustment of'the parts therelease ofthe control switch may be effected upon any predetermined temperature rise of the. heated device. It will further be observed that by giving member 17 and the notched portion of the operating member 15 an appreciable overlapping engagement, that by moving the pointer 34 the release of the switch may be insured at intermediate temperatures between prescribed li .That is to say, assuming that the itch will be automatically released at a predetermined temperature with the pointer 34 directed to the point of the iron, if the pointer then be moved in a clockwise direction it will cause relative adjustment between the members 17 and 26 to cause the switch 12 to be released at a lower,

or higher temperature in accordance with the character ofthe screw-threads and to a degree dependent upon the pitch of the screw andthe degree of movement of the pointer. Movement of the pointer in an aInti-clockwise direction would have an opposite effect. r The particular construction of the switch release device herem illustrated and debase of the section 1 and the strip 21 dispensed with. Also the switch release device might be located in other parts of the heated device, but inasmuch as it is the working face of the heated device that it is desired to regulate I prefer to locate the releasing device in as close proximity to the Working face as ispracticable.

It will be seen that as the member 26 is rocked, as above set forth,if a rigid connection between'the same and the member 21 was provided a lateral strain would be exerted upon the part 29 and the other parts connected therewith. The connection between the members 29 and 26 illustrated is designed to eliminate this tendency and does so by allowing a slight lateral, or pivotal movement of the member 29 independently of the member 26.

Having thus described my invention what I claim as new and desure to secure by Letters Patent is:

1; In combination, an electrically heated device, a quick make and break control switch therefor biased to disconnect the same from circuit a member for retaining said switch in circuit closing position and a temperature responsive device comprising rigid parts for moving said retaining memher to release said switch.

2. In combination, an'electrically heated device, a circuit controlling device therefor biased to disconnect the same from circuit, a member for retaining said device in circuit closing position, and a temperature responsive device entirely comprising rigid parts, said temperature responsive device inherently tending to hold said member in retaining position and being adapted under predetermined temperature conditions to move said member out of retaining position.

3. In combination, an electrically heated device having a circuit controlling switch tending to stand in a predetermined position, a longitudinally movable member for retaining said switch in another position, and a temperature responsive device operatively connected to said retaining member, said temperature responsive device comprising rigid parts adapted under predetermined teniperature conditions to impart a longitudinal movement to said member.

4- In combination, an electrically heated device having a circuit controlling switch ture responsive device operatively connected to said retaining member and angularly disposed thereto, said temperature responsive device having a plurality of rigid parts adapted under predetermined temperature conditions to cooperate to move the retaining member.

6. In combination, an electrically heated device, a circuit controlling device therefor tending to move from one position and having a sliding retaining member, a temperature responsive device operatively connected to said retaining member and angularly disposed thereto, said temperature responsive device having a plurality of rigid parts adapted under predetermined temperature conditions to cooperate to move the retaining member, said temperature responsive device having an inherent tendency to hold said retaining member in retaining position.

7.-In combination, an electrically heated device, a control switch therefor biased toward a predetermined position, a longitudinal movable member for retaining said switch in another position, and a temperature responsive device comprising a plurality of rigid parts, one of said parts being movable relatively to and by the expansion of another, said relatively movable part being operatively connected to said retaining member to move the same under temperature conditions.

8. In combination, an electrically heated device,.a control switch therefor biased to.- ward a predetermined position, a longitudinally movable member for retaining said switch in another position, and a temperature responsive device comprising a plurality of rigid parts, one of said parts being movable relatively to and by the expansion of another, said relatively movable part be- -ing operatively connected to said retaining member to move the same under different temperature conditions, said temperature responsive device having an inherent tendency to hold said retaining member in retaining position.

9. In combination, an electrically heated device,a control switch therefor biased torocking member and a rigid and stationaf-ily mounted bar adapted under predetermined temperature conditions to expand to actuate said rocking member.

10. In combination, an electricall heated device, a control switch therefor biased toward one position, a lon 'tudinal movable retaining member for hol 'ng said switch in another position, and a temperature responsive device operatively connected with said retaining member to move the same out of holding osition under temperature conditions, sai eluding a rigi rocking member and a ri 'd and stationarily mountedbar adapted un er predetermined tem erature conditions .to expand to actuate said rocking member, said temperature responsive device inherently tending to move said rocking member to a predetermined position under other tem-' perature cdnditions.

11. In an. electrically heated device, in combination, a device tending to break circuit, a movable member for retaining said device in circuit closing position, a temperature responsive device, and a screw-threaded coupling for operatively connecting said temperature responsive device tosaid taining member to operate the same, one member of said cou ling being revoluble at will to adjust said member relatively.

12. In combination; an electrically heated iron, a control switch therefor havin actuating, member in dle of said iron, sai switch being'biased in one directionja retainin holding said switch in a pre etermined position, and a temperature responsive device comprising rigid parts arranged in proximity to the working face of the iron for temperature responsive device incontrol switch therefor biased to disconnect 'device and retaining w an (proximity to the an member for actuating said retaimng member under pre 6 determinedconditions to release said switch.-

13. In combination, an electrically heated iron, a control switch therefor arranged in the handle thereof, said'switch being biased circuit, a latching member forlmlding said switch in circuit closing positio and a temperature responsive device comprising rigid parts for actuating said latching member-to close said switch under predetermined con ditions, said temperature responsive device being in close proximity to the working face of said iron. V

14. In co binatiorr, an electric iron, a

in a direction to disconnect said iron from control switc therefor arranged within the,

mined conditions, said device comprising a handle thereof, said switch being biased to open circuit position and having an operating member movable axially of the handle, a longitudinally movable latching member for said switch operating member disposed perpendicularly thereto, and a temperature responsive device within said iron and operatively connected to said latchin member to actuate the same under pre etermined conditions, said temperature responsive de- Vice comprising rigid parts.

1-5. In combination, an electric iron, a control switch therefor biased to disconnect the same from circuit, a lon 'tudinall movable retainin member for ho ding sai switch in circuit 0 osing position, and a temperature responsive device for actuatin said longitudinally mova'ble member un er predeterrocking member connected to said retaining 5 member and a longitudinally expansible member for actuating said rocking member. 16. In combination, an electrle iron, a control switch therefor biased to disconnect the-same from circuit, a longitudinally movable retaining member for holding said switch in circuit closin position, and a temperature responsive evice for actuating said longitudinally movable member under predetermined conditions, said device. comprising a rocking member connected to said retaimng member and a longitudinally expansible member for actuating s'aid rocking member, said expansible member and said rocking member normally tending to hold 0( said retaining member in effective position. 17. In' combination, an electric iron, a

the same fromcircuit, a longitudinally movable retaining member for holding said switch in circuit closin position, and a temperature responsive evice for actuatin said retaining member under predetermine conditions, said device comprising two strips or bars of di'fi'erent metals, one superimposed upon the other and a member onnected toone of said strips and abutting the 0nd of the other to be rockedthereby upon the expansion thereof, said roekingmember being connected to said retaining member.

I 18. In combination, an electric iron, 9. control switch therefor biased to disconnect the same from circuit, alongitudinally movable retaining member for holding said switch in circuit closin position, and a temperature responsive evice for. actuating said retainingmember under predetermined conditions, said temperature responsive device comprising two strips or'bars of difi'era cut metals one superimposed upon the other, and a member having a, right angle portion, one side thereof abutting against the end of the up 1' strip orbar, and the other side thereo being set into a recess in the lower strip or bar and underlying the lower edge of the upper strip or bar, whereby said In witness whereof, I have hereunto submember is normally held in a predetermined scribed my name in the presence of two witposition'and tilted-by relative movement of nesses.

said bars under temperature variations, said HARRY W. DENHARD. 5 member being connected to said switch re- Witnesses:

taining mem er to actuate the same under ALFRED HALvERsoN,

predetermined conditions. M. R. Fnnms. 

